If someone asks you
Hey Indiver! Did you see Star Wars movie last week?
Should I reply
Yes, I saw the movie. It was quite interesting.
Yes, I have seen the movie. It was quite interesting.
I find difficulty when speaking. I have to think between past indefinite and present perfect.
I usually use present perfect when I have to use those words like already,just or I know that if some work i have done few minutes back.
Please don't use Grammar rules to explain me. I am not preparing for exam. I want to know what is in your mouth tongue while answering above question's answer. Please don't say as well that we can use either because if you were to answer, you use only one sentence instantaneously. I just want to know why your mouth tongue has spoken in that way.